This invention concerns novel heterocyclic amide derivatives and, more particularly, novel amides derived from benzoheterocyclylalkanoic acids (and related tetrazoles and acylsulphonamides), which antagonise the pharmacological actions of one or more of the arachidonic acid metabolites known as leukotrienes (hereafter referred to as "leukotriene antagonist properties"). The novel derivatives are useful whenever such antagonism is desired. Thus, such compounds may be of value in the treatment of those diseases in which leukotrienes are implicated, for example in the treatment of allergic or inflammatory diseases, or of endotoxic or traumatic shock conditions. The invention also provides pharmaceutical compositions containing the novel derivatives for use in such treatments, and processes and intermediates for the manufacture of the novel derivatives.
In U.S. Pat. Nos. 3,271,416 and 3,470,298 there are described 5-acetamido-1-benzylalpha, 2-dimethylindole-3-acetic acid derivatives and (5-acetamido-1-benzyl-1H-indazol-3-yl) oxyacetic acid derivatives, respectively, as antiinflammatory compounds; N-acyl derivatives of 6-amino-1-benzylindazole have been described (see E. Hannig, et al., Pharmazie, (1974), 29: 685-7); and 6-(acetylamino)-2,3-dihydro-4H-1,4-benzoxazine-4-propanoic acid methyl ester has been registered (Chemical Abstracts Registry Number 27802-53-5) Chem. Abs. 74: 4635(M). We have now discovered a series of benzoheterocyclic derivatives which have an amidic substituent in the benzenoid ring and which unexpectedly possess the property of antagonising one or more of the arachidonic acid metabolites known as leukotrienes and this is the basis for our invention.